Electrical Engineering
Electrical Engineering MCQs with Answers
Electrical engineering MCQs with answers and detailed explanations for PEC, NTS, WAPDA and engineering job tests. Machines, circuits and power systems. Take a scored quiz instead →
Silicon steel is chosen for core construction in electrical machines because it offers:
AHigh electrical conductivity
BHigh mechanical copper strength
CLow resistance to eddy currents
DLow hysteresis loss and high magnetic permeability
The hysteresis loop area of a ferromagnetic material represents:
ATotal magnetic flux density
BPermeability of material
CEnergy loss per unit volume per cycle
DCoercive force required
Lenz’s Law in electromagnetic induction directly complies with which conservation law?
ALaw of Conservation of Mass
BLaw of Conservation of Charge
CLaw of Conservation of Momentum
DLaw of Conservation of Energy
Kelvin’s Double Bridge is designed to eliminate lead and contact resistances when measuring:
AMedium resistances
BVery low resistances (< 1 ohm)
CInductive reactances
DHigh insulation resistances
In a 3-phase delta-connected balanced load, the line current I_L is equal to:
A3 * I_ph
Bsqrt(3) * I_ph
CI_ph / sqrt(3)
DI_ph
A Megger is a special type of instrument designed specifically to measure:
ALow armature resistance
BHigh insulation resistance
CLine frequency
DAC power factor
Salient-pole rotors are preferred in alternators driven by:
AHigh-speed gas turbines
BHigh-speed steam turbines
CLow-speed hydro turbines
DNuclear reactors
In a 3-phase star-connected balance system, the line voltage V_L is related to phase voltage V_ph by:
AV_L = 3 * V_ph
BV_L = V_ph
CV_L = V_ph / sqrt(3)
DV_L = sqrt(3) * V_ph
In an alternator, using short-pitched coils primarily helps to:
AIncrease leakage reactance
BIncrease total generated voltage
CReduce mechanical friction
DEliminate specific high-frequency harmonics from induced voltage
What type of rotor is used in steam-turbine driven alternators (turbo-generators) running at high speeds (3000 RPM)?
AWound slip-ring rotor
BSalient pole rotor
CSmooth cylindrical rotor
DSquirrel cage rotor